Lady Gaga says paying tribute to the late David Bowie at the Grammys is probably the most challenging thing she's done in career because the icon influenced her greatly and helped shape her identity.

Gaga performed an extended tribute to Bowie at the Staples Center in Los Angeles on Monday, channeling the legend as Ziggy Stardust as she ran through his hits, including "Space Oddity," ''Let's Dance," ''Changes" and "Heroes."

Days before the performance, she said in an interview with The Associated Press that performing in his honor was a bittersweet way to say goodbye to one of her inspirations.

"When I was 19 years old ... I started to live my life like him. I began to consume art and fashion and art history and a combination of those things, performance technique ... and I only hung out with people that were artists and that was the way that he was and I learned that from him," she said. "What I'm trying to say is there's people that love David Bowie, and then there's David Bowie fans, and there's Bowie kids, who live like him ...and I can't express to you, I don't know who I'd be if I didn't have (him as) a figure in my life. I don't know what my identity would be."

Bowie died of cancer at age 69 on Jan. 10. Gaga said she never met Bowie, but that they "were pen pals."

The pop star was already set to perform at the Grammys, but asked to sing in tribute of Bowie after he died. And days before the Grammys, she got a large tattoo of Bowie's face on the side of her body.

"I've been wanting to get one for a long time. I was thinking about how there's a lot of my fans that have Lady Gaga tattoos, some of them are really covered, and I always thought it was so badass the way that they were so committed to my music," she said. "I have a lot of ink already on my body, different sort of artistic prayers and thoughts and things that mean something to me, but I always wanted to get a tattoo of somebody that changed my life. And he really did."

Her Grammy performance was a collaboration with Intel technologists and included lighting, audio and projection systems to match with Gaga's performance to pay homage to Bowie. The performance was highlighted by visual effects, including animation of a spider crawling on her face. She called Intel "fabulous partners for me because we're both interested in innovation."

"(I'm) trying to always take things to places that no one's ever taken them before," she said.